JPS63201644A - Automatic original carrying device - Google Patents

Abstract

PURPOSE:To easily and securely position the front end of an original by stopping driving a paper discharge roller while clamping the rear end of the original to be discharged by the paper discharge roller to specific length according to measured original length, and then redriving the roller a constant time later. CONSTITUTION:When the original is detected by an original detector 28 at the time of the discharging of the original, the conveying speed of the discharging roller 12 is reduced to about 1/2-1/4, for example, before the original comes not to be detected by the original detector 28 according to the length of the original which is measured previously. Further, the driving of a belt driving motor is stopped for a certain time before the original detector 28 comes not to detect the original. The discharge roller 12, therefore, stops and the original is stopped temporarily while clamped by the discharge roller 12. The driving of the driving motor is restarted a constant time later and the original is discharged continuously at a speed about 1/2-1/4 as fast as normal. Consequently, the front end of the original can be stopped at a reference position in an invariably normal state.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an automatic document conveying device that transports a document to a scanning position and discharges the document after scanning, in order to optically scan an image on the document.

<Prior art> An automatic document feeder is provided, for example, in correspondence with the document placement table (transparent glass plate) of the main body of a copying machine, and automatically conveys the document to the placement table and transfers the document after processing. It is something that is discharged. That is, a large number of original documents, for example, are stacked on the paper feed section, and the stacked originals are conveyed one by one to the above-mentioned placement table according to control commands from the main body of the copying apparatus, and are positioned at specified positions. This document is optically scanned by the action of the document scanning means, and after this scanning is completed, it is discharged to the position of the paper discharge tray. Then, when the ejection of the original is completed, the next original is conveyed to a specified position on the mounting table, and the above-described operation can be repeated.

According to the automatic document feeder as described above, a bait is provided facing the document placement table in order to convey the fed document to a specified position (reference position) on the document placement table. .

Therefore, in order to position the document at the specified position on the loading table, the drive of the table must be stopped from the constant speed running state before the document reaches the specified position (before the leading edge of the document contacts the stopper, for example). The paper is moved by inertia, and the leading edge of the document is brought into contact with the stopper. If the configuration is like this,
Because the inertia of the Be/7) was still large, the leading edge of particularly thin originals would break or wrinkle.

Further, when the document scanning is completed and the document is discharged to the discharge tray, the document is discharged at the same speed as when it is transported. As a result, the documents being ejected fly out onto the ejection tray at a considerable speed. This distance varies depending on the size and thickness of the document, and some documents may jump over the output tray. In order to prevent this and to align the ejected originals, a catch device is provided to restrict the leading edge of the ejected originals and align the originals on the ejection tray.

<Problems to be Solved by the Invention> In the conventional automatic document feeder described above, in order to prevent the leading edge of the document from being bent or wrinkled, and to prevent the ejected document from scattering, the length of the document to be conveyed is measured. , before the document reaches the specified position, gradually reduce the conveyance speed of the document.
Japanese Unexamined Patent Application Publication No. 60-55332 ``Automatic Document Feeder'' discloses that the conveying speed of the belt is set to zero at the timing when the document reaches a predetermined position. According to this prior art, when ejecting a document, the rotational speed of the motor is controlled so that the speed of the document is gradually increased and the document is ejected from the document ejection port at a constant speed.

According to the conventional device described above, when the voltage applied to the motor is lowered to gradually reduce the conveying speed of the document, the motor stops rotating even though the voltage is applied, and the stopping position of the document varies. There are many people who have gotten used to it.

Therefore, it is necessary to use an encoder that allows the conveyance distance per one pulse of the motor to be extremely small, which increases costs including motor drive control. Moreover, since the ejected originals scatter, special means for aligning the originals is required.

SUMMARY OF THE INVENTION According to the present invention, it is an object of the present invention to provide an automatic document feeder that can reliably position the leading edge of a document using very simple means.

Another object of the present invention is to control the conveyance of ejected originals so that they do not jump over the original when they are ejected.

Means for Solving the Problems> According to the automatic document feeder of the present invention, a means is provided for measuring the length of the document to be conveyed until the document reaches a specified position on the document placement table, and the leading edge of the document is Before reaching the reference position of the document placement table, the table for transporting the document to the document placement table is decelerated from the constant speed, and the sheet is stopped a certain period of time after the leading edge of the document reaches the reference position. belt control means,
When the document is ejected, the belt is stopped before the trailing edge of the document is not detected by the document detection means provided near the discharge roller based on the document length measured by the document length measuring means, and after a certain period of time has elapsed. The present invention is characterized by comprising means for re-driving and controlling the discharge roller and the like.

Effects> According to the automatic document conveying device of the present invention, the conveyance speed of the document decreases before the specified position on the placing table, and the leading edge of the document reaches the specified position (
It will be stopped a predetermined time after reaching the reference position) K-.

Then, for example, once scanning of the original is completed, the original is ejected, conveyed, and ejected via the ejection roller.The document stops before the trailing edge of the original (rear end in the feeding direction) passes the ejection roller. The vicinity of the end portion is held between the discharge rollers and conveyed again, and discharged onto the discharge tray. In this case, the distance that the document flies out when it is ejected is suppressed,
They are arranged on the ejection tray and ejected.

<Example> Fig. 1 is a cross-sectional view showing the overall configuration of an automatic document feeder according to the present invention, and Fig. 2 is a plan view of the automatic document feeder as viewed from the back in a state opened to the main body of the copying machine. be.

In the figure, reference numeral 1 denotes a mounting table made of a transparent glass plate provided on the upper part of the main body of the copying apparatus and on which the original is placed.

Reference numeral 2 denotes a main body of the automatic document conveying apparatus which is provided to be openable and closable with respect to the placing table 1, and 3 is a paper feed table for placing documents in the automatic document conveying apparatus and inserting and feeding them one by one. This paper feed table 3 is fixedly provided on the upper part of the main body of the copying apparatus, and is not opened or closed together with the main body 2 of the automatic document conveying apparatus. A stopper 1-1 serving as a reference end for regulating the leading edge of the document is provided at one end of the placing table l.

The automatic document feeder main body 2 has a hinge mechanism 4 attached to the negative side end, and a portion 5 fixed to the copying device side and a shaft portion 7 to a portion 6 fixed to the feeder main body 2 side.
Since it is provided rotatably around the shaft 7, it is configured to open and close around the shaft 7. The automatic document feeder main body 2 includes a paper feed roller 9 for feeding the document on the paper feed tray 3 into the exterior 8, an endless conveyor belt 10 for feeding the document to the loading table 1, and a conveyor belt 10 on the exterior 8. Place the original onto the paper output tray 80 through the output port 1
1, a discharge guide 13 for guiding the document to the discharge roller 12, and a switching claw 14 for guiding the document to the discharge guide 13 during discharge. The discharge port 11 is formed by removing a part of the external device.

The conveyor belt 10 is stretched between rollers 15 and 16 arranged corresponding to both ends of the mounting table 1.
It is driven according to the rotation of 5. The roller 15 is rotatably provided via a bearing or the like between a frame 18 whose one end is fixed to a support plate 17 attached to an external device. Further, the roller 16 is rotatably provided via a bearing or the like to a support member 20 that is fixed to a support plate 19 that is attached to an external device parallel to the support plate 17. The above roller 15
One end of the shaft extends through the frame 18 and is fixed to a pulley 22 to which the rotational force of a belt drive motor (for example, a DC motor) 21 is transmitted.

A drive belt 23 is stretched between the flywheel 22 and a pulley connected to the shaft of a drive motor 21, and the roller 15 is rotated as the motor 21 rotates.

Furthermore, a discharge roller 12 is rotatably provided on the frame 18 via a bearing or the like, and one of the rollers 12
．． The configuration is such that the rotational force from the C motor 21 is transmitted.

The conveyance speed of the document by the discharge roller 12 and the conveyance belt 10
The transport speed is set to be almost the same as the transport speed. In addition to the ejection roller 12, the shaft of the paper feed roller 9, the ejection guide 13, etc. are attached to the frame 18, and are configured as one unit. The paper feed roller 9 has a structure in which rotational force from a motor (not shown) (DC motor) is transmitted to its shaft,
10 etc. are driven separately.

In the vicinity of the paper feed roller 9, document detectors 24 and 25 are arranged to detect a document inserted between the rollers 9. The document detectors 24 and 25 use, for example, a light detection type sensor consisting of a light emitting and a light receiving element. When the document detector 24 detects the leading edge of the document, the paper feed roller 9 is driven to feed the document onto the conveyor belt 10. When the document detector 25 detects the document to be fed, the drive of the paper feed roller 9 is stopped and the document is temporarily waited at that position. The shaft 90 of this paper feed roller 9 has one end attached to the frame 18.
A clock disk 26 is fixed to the protruding end thereof, and has slits formed at equal intervals for detecting the length of the document. An optical sensor 27 consisting of a light-emitting and light-receiving element is provided between the clock disk 26. By counting the slit signals (clock pulses) output from the optical sensor 27, the document passing through the paper feed roller 9 is detected. Length can be measured.

Further, between the passage between the paper feed roller 9 and the conveyance belt 10, a switching pawl 14 in the conveying direction is rotatably provided, and normally rotates counterclockwise under its own weight, so that the tip of the switching pawl 14 The rotation stops when it comes into contact with the guide section that forms the document path. Therefore, when the document is fed by the paper feed roller 9, the switching pawl 14 is rotated clockwise and guides the leading edge of the document in the direction of conveyance, but when the document is reversed and conveyed in the opposite direction, the The tip is guided along the upper surface of the switching claw 14 to a discharge path formed by the discharge guide 13. A document detector 28 for detecting a document to be discharged is arranged near the discharge roller 12 on the discharge path. This document detector 28 has the same structure as the document detectors 24 and 25. The document detector 28 sends a document detection signal to the control circuit, and the control circuit controls the document by reducing the conveyance speed of the trailing edge of the document to the discharge port based on the previously measured length of the document.

As described above, the roller 15 that drives the conveyor belt 10, the paper feed roller 9, the discharge roller 12, the discharge guide 13, the switching claw 14, the drive motor 21, and the various detectors 24, 25, and 2.
8 etc. are integrally attached within the frame 18 as a unit. Corresponding to the paper feed roller 9, a roller 29 that is in contact with the paper feed roller 9 is rotatably provided on the paper feed table 3 side. Further, the conveyor belt 10 on the main body side of the automatic document conveyor is provided with a driven roller 3 in order to convey the document conveyed on the first surface of the document placing table effectively without slipping.
0 are arranged within the bell) 10 at appropriate intervals. Both ends of the shaft 31 of the driven roller 30 are rotatably supported by a shaft support 32 and are held movably in the vertical direction.

Therefore, when the automatic document transport device is closed as shown in FIG. 1, the rollers 30 move downward due to their own weight and act to press the transport belt 10 against the surface of the mounting table 1.

One of the pivot supports 32 is fixed to a stay 33 attached to connect the support plates 17 and 19, and the other is attached directly to an external device. In addition, in Figure 2, 35
is a control circuit board for driving and controlling the automatic document feeder, and it drives and controls the drive motor 21 etc. based on detection signals from various detectors, command signals from the copying machine main body, etc. Outputs a signal to the copying machine main body side. Also,
Reference numerals 36 and 37 denote collars that are fixed to the bearings of the shafts of the rollers 14 and 15, and are used to maintain a constant distance between the conveying table 10 and the original table 1.

In the automatic document feeder configured as described above, the control operation for document feeding according to the present invention will be described below.

A document to be copied is inserted along the paper feed table 3, and when the leading edge of the document is detected by the document detector 24, the paper feed roller 9 is rotated. As a result, the original is caught between the paper feed roller 9 and the contact roller 29 and fed. When the document detector 25 disposed after the paper feed roller 9 detects the detection, the drive of the paper feed roller 9 is stopped, and the document enters a standby state at that position. The signal indicating this waiting state is
The information is sent to the copying machine, and the copying machine prepares to start copying. Then, by operating the copy switch on the copying machine or the start switch on the automatic document feeder,
A command signal for starting document conveyance is output from the copying machine main body side to the conveyance device side. As a result, the paper feed roller 9 and the conveyance belt 10 are driven simultaneously. That is, the paper feed roller drive motor (FIG. -f) and the drive motor 21 of the conveyor belt 10 are activated.

As described above, the waiting original is conveyed to the original placing table l. While the document is being conveyed, the length of the document is measured. This is done by counting the clock signal generated based on the clock disk 26 of the rotating shaft 90 of the paper feed roller 9 in a control circuit until the trailing edge of the document passes the document detector 24, and adding 1 to this count. It can be measured by the sum of the value multiplied by the document moving distance per pass and the distance between the detectors 24 and 25. The measured length of the document is temporarily stored in the storage section of the control circuit board 35. When the document length is measured and the trailing edge of the document passes the detector 25, the drive of the paper feed roller 9 is stopped, and the document is conveyed on the mounting table l by the conveyance bell 1-10. Then, the paper feed roller 9 is driven and controlled in order to set the next document in a standby state.

The document conveyed by the conveyance table 10VC- is conveyed at a speed of, for example, approximately 800 to 10001117 seconds. For this document, the distance between the stopper 1-1, which is the reference end, and the leading edge of the document is, for example, 6 On toward the front, and the output to the belt drive motor 21 is lowered to maintain the speed of the conveyor belt 10~],'4( Lower it to about 300ff/5ec). In this case, it is sufficient to drive the conveyor belt 10 at the slowest possible speed, but it takes a considerable load to drive the conveyor belt 10.
The speed of the motor 21 cannot be controlled. In such a deceleration state, the leading edge of the document is brought into contact with the stopper 1, Ic, and after a period of time commensurate with the overrun distance of about 1.OU after contact, the transport table 10 is driven (the motor 21 is driven). stop. The purpose of this overrun is to return the document that has been fed diagonally to its normal state, and also because the inertia force varies depending on the individual devices due to slipping between the conveyor belt and the document or even if the belt drive motor 21 is stopped. Therefore, this is to avoid the case where the leading edge of the document does not reach the stoppers 1 and C. In this way, the document is accurately conveyed to a predetermined position (reference position) and stopped at that position. When a signal indicating the state at this time is sent to the copying machine main body, the loading table 1
Exposure for optically scanning the image of the upper original begins, and image formation begins.

Copying is started as described above, and once the preset number of copies have been completed, especially when exposure scanning of the original is completed, a command signal to eject the original on the mounting table 1 is transferred to the transport device 2. Then, the conveyance device 2 starts the ejection operation. In this case, the belt drive motor 21 is rotated in the opposite direction to the previous rotation direction.

Therefore, the document is reversed and conveyed toward the feeding side with the trailing edge becoming the leading edge. The conveyance speed at this time is set to be approximately the same as the conveyance speed during feeding, for example.

Then, by the action of the switching claw 14, the original is transferred to the ejection guide 13.
You will be guided to the discharge path consisting of . The document guided to the ejection path is held by ejection rollers 12 provided opposite to the ejection port 11, and ejected onto the ejection tray 80 on the upper surface of the external device. here.

When the document is ejected, when the document is detected by the document detector 28, based on the length of the document measured in advance, the document is detected by the document detector 28.
At step f), the conveyance speed by the discharge roller 12 is reduced to approximately 0.000 to V4. Furthermore, before the original is not detected by the original detector 28 (approximately 10ff), the drive of the bait drive motor 21 is stopped for a certain period of time (for example, approximately 100m5e).
c) Let. As a result, the discharge roller 12 stops, and
Is the original on ejection roller 12F? - You will have to stop temporarily while being held. After this certain period of time has elapsed, the drive motor 2
1 is restarted, and the document continues to be ejected at a speed of approximately 1/2 of the constant speed = V4.

As described above, the document is stopped for a certain period of time with the trailing edge of the document (the leading edge when the document is transported to the reference position) being held between the discharge rollers 12, and then discharged onto the discharge tray 80 at a low speed after being driven again. Ru. in this case.

Since the leading edge (head) of the document when stopped hangs down onto the discharge tray 80 due to its own weight, it will not scatter after being conveyed again. Furthermore, since the document is driven at a low speed after being conveyed again, the documents are prevented from scattering and the documents to be discharged are effectively aligned on the discharge tray 80. In other words, the scooking properties are improved. When the ejection of the original is completed, if the primary original is in the position of the paper feed roller 9, the original is conveyed and ejected according to the procedure described above.

<Effects> According to the automatic document feeder of the present invention, the leading edge of the document can always be stopped at the reference position in a normal state. In this case, accurate positioning is possible regardless of the thickness of the document.

Furthermore, the documents to be discharged can be effectively aligned without flying onto the discharge tray.

[Brief explanation of the drawing]

FIG. 1 is a sectional side view showing a specific example of an automatic document feeder according to the present invention, and FIG. 2 is a plan view of the automatic document feeder as seen from the back side. 1: Placement table, 2: Automatic document transport device, 3: Paper feed table, 9:
Paper feed roller, 10: conveyance belt, 11: discharge port, 12:
Discharge roller, 13: Discharge guide, 15.16: Belt drive roller, 21: Belt drive motor, 24.25, 2
8: Original detector, 26: Cloth disk, 2'7: Optical sensor, 35: Control circuit board.

Claims (1)

[Scope of Claims] 1. When conveying a copy original onto a mounting table for image exposure, the document is transported so that the leading edge of the original stops at a reference position on the mounting table, and when the image exposure is completed, the original is ejected to a document output tray. In an automatic document feeder comprising: a measuring means for measuring the length of the document being conveyed to a reference position; and a conveyance control that reduces the conveyance speed of the document before the leading edge of the copy document reaches the reference position and then stops the document. means, an ejection roller for ejecting the original to the ejection tray, a detection means provided near the ejection roller to detect the ejected original, and a length of the original measured by the measuring means in response to an original detection signal from the detection means. an original document discharge control means for stopping the drive of the discharge rollers while the rear end of the discharged document is held between the discharge rollers for a predetermined length based on the above, and driving the discharge rollers again after a certain period of time. Device. 2. An automatic document conveying device characterized in that the document discharge control means controls the drive speed of the discharge roller to be reduced by re-driving.